Isotype Controls

Negative controls are essential to conducting thorough and meaningful experiments. Antibodies can bind to other molecules, especially other proteins, in non-specific or undesired ways. To show that identification of a particular band on a Western Blot or staining for a cell-surface marker in flow cytometry using an antibody is specific, a negative control may be used which should not result in similar band patterns or staining.

Isotype Controls

Isotype controls are a particular type of negative control that feature the same Fc-region as the antibody the actual experiment is being conducted with but a variable region that should not bind antigen in the experiment. The Fc-region can interact specifically with Fc-Receptors or complement, hence it is necessary to control for this “background” when staining for cell-surface markers (see also our antibody resource). These interactions may even be across species e.g. Rat IgG with mouse Fc-receptors. Therefore, a diverse panel of isotype-controls was traditionally required when performing flow-cytometry. See also our Fc-Silent™ product range for practical solutions to this problem.

Standardised Controls Offered by Absolute Antibody

Antibody engineering makes possible the generation of a standardised panel of isotype-controls with the same “specificity” (i.e. derived from the same original antibody) – this can reduce experimental complexity. The panels benefit from the superior reproducibility and purity we obtain using our recombinant production platform.

Absolute Antibody currently offers isotype-control panels derived from four different antibodies: Anti-NP, anti-fluorescein, anti-beta galactosidase (from E. coli) and an antibody called MOPC-21 with unknown specificity. All are available in human, mouse, rat, rabbit and hamster isotypes.

Don’t see the format you need? Just contact us and we’ll be happy to help you.